The present invention relates generally to a method and system for head retraction and cartridge ejection in a data storage device, and, in one exemplary embodiment, to an engine module for actuating a head retraction mechanism and a cartridge ejection mechanism in a data storage device.
Currently, a number of data storage devices exist for the storage of digital data on recording media. For example, magnetic storage devices can be utilized for the storage and/or retrieval of digital data on magnetic recording media, optical storage devices can be utilized for the storage and/or retrieval of digital data on optical recording media, and semiconductor storage devices can be utilized for storage and/or retrieval of digital data on semiconductor recording media. In such devices, the recording media can be permanently mounted or removable. Examples of magnetic data storage systems which accept removable magnetic disk cartridges include the ZIP(copyright) drive device, manufactured and marketed by the Iomega Corporation.
In many data storage devices, recording heads are provided to control the reading and/or writing of the data to the media. Such heads can be very sensitive to shock forces and generally should be protected when not in use, such as during transportation or when the recording media is not present. Accordingly, systems have been utilized which retract the head to a safe or protected position during such times.
For example, in a magnetic disk drive device, when a removable magnetic disk is placed in the drive, read/write heads are then permitted to move away from their protected position and toward the read/write position which allows the heads to read and write data to the disk. When the disk is removed, the heads are then retracted to a protected or parked position. A latch can then engage the head actuator to prevent movement of the heads toward the unprotected read/write position.
Various engine systems and components have been utilized for retracting the recording heads and/or initiating the ejection of the cartridge in such data storage devices. In one such system, a D.C. motor, opposed by a spring, engages a pivoting spur gear which engages a head park lever or arm. The motor withdraws the head park lever and allows the heads to read from and/or write to the media. When the direction of the D.C. motor is reversed, the pivoting gear immediately disengages the head park lever, and the spring, acting alone on the head park lever, accelerates the heads to the parked position. Such an uncontrolled retraction of the heads via the spring can cause a large shock to the heads and/or to the media, posing the risk of damage. While damping grease has been utilized to slow down the parking of the heads in such a system, the viscosity of damping grease can vary with temperature, providing inconsistent results. Moreover, the application of damping grease introduces an extra manufacturing process that is expensive and subject to variability in application.
In addition, the manufacture of such head retraction and ejection systems has generally required several components which must be fastened in a small space. As can be understood, the assembly of many pieces of such a system can be time consuming, difficult, expensive, and can require special tools. Moreover, a system having such multiple moving components can suffer from reliability problems in repeatedly performing head retraction movements.
Accordingly, there is a need for a head retraction system for a data storage device which retracts data storage heads in a more controlled manner and with less risk of damage to the recording heads and/or media. Moreover, there is a need for head retraction and cartridge ejection systems which are easier to manufacture and more reliable in operation.
It is an object of the present invention to obviate one or more of the above-described problems.
It is an object of at least one embodiment of the present invention to provide an improved recording head retraction system.
An object of at least one embodiment of the present invention is to provide a recording head retraction system which retracts recording heads in a controlled manner.
It is an object of at least one embodiment of the present invention to minimize damage to a recording head.
An object of at least one embodiment of the present invention is to provide head retraction and ejection systems which are easier to assemble.
One object of at least one embodiment of the present invention is to provide a head retraction and ejection system which requires fewer separate parts.
It is an object of at least one embodiment of the present invention to provide a head retraction and ejection system which is less prone to failure.
An object of at least one embodiment of the present invention is to provide a head retraction system which requires less space.
The above objects are provided merely as examples, and are not limiting nor do they define the present invention or necessarily apply to every aspect thereof. Additional objects, advantages and other novel features of the invention will be set forth in part in the description that follows and will also become apparent to those skilled in the art upon consideration of the teachings of the invention.
To achieve one or more of these objects, one embodiment of the present invention includes a data storage device, comprising, a recording head, a recording head movement assembly configured to selectively move the recording head, and a head retraction system. The head retraction system comprises a motor actuator, a head retraction arm, and a gear assembly driven by the motor and in contact with the head retraction arm. The head retraction arm is movable in a head loading direction between a head parked position and a head loaded position, and is movable in a head retraction direction between the head loaded position and the head parked position. The head retraction arm is configured to retract the recording head to the head parked position when moved in the head retraction direction. Moreover, the gear assembly is configured to remain in contact with the motor and the head retraction arm during at least part of the movement of the head retraction arm in the head retraction direction, so as to provide controlled movement of the head retraction arm in the head retraction direction.
According to one exemplary embodiment, a displaceable transmission mechanism, such as a gear mechanism for example, is driven by the motor. The transmission mechanism is displaceable in a controlled path between a first position in which the displaceable transmission mechanism contacts a head retraction mechanism (comprising the head retraction arm) such that the head retraction mechanism is movable by the actuator, and a second position in which the displaceable transmission mechanism contacts an ejection mechanism such that the ejection mechanism is movable by the actuator. A load member in contact with the displaceable transmission mechanism provides friction such that the displaceable transmission mechanism may be displaced between the first and second positions under force of the actuator. The load member can be integral with a base upon which the displaceable transmission mechanism is mounted, and the controlled path may be defined by a slot integral with the base. A friction member can be provided on the displaceable transmission mechanism and can contact the load member. The friction member can comprise a friction disk, such as a rubber disk for example, which does not have gears or knurls. The displaceable transmission member can comprise a gear which is rotatably displaceable in the path defined by the slot by the friction between the rotating friction member and the load member which is contacted by the friction member. The motor may be held by using a biasing member which can be integral with the base and movable to an open position so as to provide clearance for the motor to be placed on the base. A torsional biasing member can provide a biasing force in a torsional direction on the head retraction arm, the biasing force acting on the head retraction arm and tending to move the head retraction arm about a pivot point. The torsional biasing member can be mounted partially within the head retraction mechanism and can compress between a stop surface on the head retraction mechanism and a stop surface on the base as the head retraction mechanism moves.
Still other advantages and aspects of various embodiments will become apparent to those skilled in this art from the following description wherein there is shown and described exemplary embodiments of this invention simply for the purposes of illustration. As will be realized, the invention is capable of other different aspects and embodiments without departing from the scope of the invention. Accordingly, the advantages, drawings, and descriptions are illustrative in nature and not restrictive in nature.